Image sensor with epitaxially self-aligned photo sensors

[0011]Embodiments of a pixel, an image sensor, an imaging system, and methods of fabrication of a pixel, image sensor, and imaging system having improved image lag, noise, and long wavelength sensitivity characteristics are described herein. In the following description numerous specific details are set forth to provide a thorough understanding of the embodiments. One skilled in the relevant art will recognize, however, that the techniques described herein can be practiced without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring certain aspects. For example, although not illustrated, it should be appreciated that image sensor pixels may include a number of material layers disposed on the front side or backside (e.g., pixel circuitry, dielectric layers, metal stacks, color filters, microlenses, etc.), as well as other conventi